In view of improving a fuel efficiency, a power performance, or the like, of a vehicle, a development of a transmission or an automated transmission apparatus has been preceding based on a conventional synchromesh type manual transmission.
JP1981(56)-127842A (see FIG. 1, corresponding to EP0034411A3) and DE3530017A1 respectively disclose a transmission which includes two clutch mechanisms (first and second clutches) for transmitting a power to a transmission from an engine, and includes plural input shafts (first and second input shafts) of the transmission. With the configuration of each disclosed transmission, the power can be transmitted to the first input shaft from the first clutch, and the power can be transmitted to the second input shaft from the second clutch. Further, the first input shaft is provided with gears for first, third, and fifth shift stages, and the second input shaft is provided with gears for second, fourth, and sixth shift stages.
A shift operating apparatus is disclosed in WO01/84019A1 (see FIGS. 1a and 2, and columns [0034]-[0040] of a corresponding publication No. US2003/0121343A1), which includes a shift and select shaft, an inner lever (i.e., a selector) provided on the shift and select shaft, and plural shift grooves (i.e., shift fork openings) respectively provided on plural shift forks. The shift and select shaft is rotated about an axis upon a shift operation and is linearly moved in an axial direction upon a select operation. The inner lever is rotated about the axis upon a shift operation and is linearly moved in the axial direction upon a select operation. Each shift groove is engaged with a head portion of the inner lever so as to establish a predetermined shift stage. A shift-directional dimension of a recess of each shift groove is designed greater than a shift-directional dimension of the head portion of the inner lever, so that a large clearance is ensured between the head portion of the inner lever and the recess of each shift groove in the shift direction. According to the disclosed shift operating apparatus, a synchromesh mechanism of a transmission is operated in response to a shift stroke of a selected shift fork, and a predetermined gear is rotated in sync with a predetermined shaft.
A shift-directional dimension of the aforementioned clearance is formed greater than the shift stroke of each shift fork in order to prevent interference between the head portion of the inner lever and a jaw or edge portion of the shift groove at a time when the inner lever moves across the shift grooves upon a select operation.
However, according to the shift operating apparatus disclosed in US2003/0121343A1, when a direct shift operation, by which a shift change is implemented by engageably operating only one synchromesh mechanism, is performed as illustrated in FIG. 6A, the head portion of the inner lever runs a long distance until the head portion contacts with an inner wall of the shift groove. In other words, a long and idle running time is required. Further, when an indirect shift operation, by which a shift change is implemented by engageably operating plural synchromesh mechanisms, is performed as illustrated in FIG. 6B, a long and idle running time is required at the time of returning to a neutral position from a shift stage and at a time of a shift movement to another shift stage. Accordingly, the disclosed shift operating apparatus may take a time to complete a shift operation.
A need thus exists to provide a shift operating apparatus, which can reduce a time required for a shift operation to establish a predetermined shift stage. The shift operating apparatus can be applied to a synchromesh type manual transmission or an automated synchromesh type manual transmission. More particularly, the shift operating apparatus can be applied to an automated synchromesh type transmission with plural clutches.